[技术]Arizona眼睛模型 [复制链接]

简介 p6Z|)1O]  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 j+@3.^vK
 
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模型 ^=5x1<a9$  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 z;!"i~fFK  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. <Se9aD  
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光源 {`Gd  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 5C&*PJ~WA  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 *= ?|n  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 r0 )ne|&Hp  
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视网膜的散射 ddyX+.LMk  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 "L:4 7!8  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 EG;E !0  
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脚本 CF2Bd:mfZ  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： RGE(#   
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 6:O<k2=2  
余下的脚本计算与屈光度有关的所有参数。 *Ud(HMTe  
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分析 X 3$ W60Q  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ;,C]WZ.w  
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脚本代码 k(l2`I4V  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ~DI$O[KpR%  
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Dim entity As T_ENTITY 0(D^NtB7  
Dim op As T_OPERATION >w@+cUto  
Dim mat As T_MODELMATERIAL RhH1nf2UR  
Dim A As Double Y~-y\l;Tr  
Dim pupilDiam As Double &~ y)b`r  
Dim eID As Long kkF)Tro\  
Dim parID As Long *[3xc*5F/A  
Dim count As Integer &$F<]]&  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double FM >ae-L-  
Dim tlens As Double, nlens As Double :x)H!z P  
Dim curv As Double, conic As Double LdV&G/G-#D  
Dim ok As Long yZ|"qP1  
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Sub Main .p&@;fZ  
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    '用户输入对话框 'J|)4OG:  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QEhn  
        TextBox 220,21,40,21,.TextBox1 'default: 0 :TH cI;PG8  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 !hBpon  
        OKButton 40,91,90,21 ?;XEb\Kf  
        CancelButton 190,91,90,21 f'^uuO#x  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 LH8jT  
        TextBox 220,49,40,21,.TextBox2 'default: 4 [y[d7V9_o  
    End Dialog D(#f`Fj;  
    Dim dlg As UserDialog GiV%Hcx  
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    ok = Dialog (dlg) &X$T "Dp  
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    If ok=0 Then    'cancel button was pressed &9p!J(C  
        Print "Execution cancelled." /o9T [^\  
        End .$qa?$@  
    End If nqcq3o*B  
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    'Assign accommodation and pupil diameter & use defaults if field left empty \k.`xG?  
    If dlg.TextBox1 = "" Then 7K1-.uQ  
        A = 0           'Default accommodation QJGGce  
    Else WQK<z!W5  
        A = CDbl(dlg.TextBox1) z8Q!~NN-K  
    End If $YL9 vJV  
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    If dlg.TextBox2 = "" Then Ts5)r(  
        pupilDiam = 4   'Default pupil diameter jFj11w1FrA  
    Else 6#?T?!vZ  
        pupilDiam = CDbl(dlg.TextBox2) 2$JGhgDI  
    End If /4:bx#;A  
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    Print " " 1 em,/>"  
    Print "Accommodation = " & A & " Diopters" Z/#_Swv  
    Print "Pupil Diameter = " & pupilDiam & " mm" y_Y(Xx3  
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    ' Calculate new parameters with accommodation m[9.'@ye  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?\}Gi(VVE  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens pP. _%5  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U v2.Jo/Q  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `ONjEl  
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    tlens = 3.767 + 0.04*A                  'Lens thickness X'Ss#s>g  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction N9e'jM>Oos  
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    'Adjust parameters to account for accommodation P6:9o}K6  
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    '************************************************************************* |VBt:dd<  
    'Aqueous thickness (Position of Lens) TR"C<&y$j  
    '************************************************************************* [2%[~&4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :RaQ =C  
    GetCustomElement eID, entity Ot=jwvw  
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    parID = FindFullName( "Geometry.Arizona Eye" ) {keZ_2  
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    ' Delete any shift(s) in z :cT)M(o  
    count = 0 $@g]?*L:  
    While GetOperationCount(eID)>count D -}>28  
        GetOperation eID, count, op h [TwaR  
        If op.Type="ShiftZ" Then Njq}M/{U  
            DeleteOperation eID,count [BWq9uE  
            count=count-1 o<`vh*U@,4  
        End If `+7F H  
        count=count+1 fqNh\~kja  
    Wend 6EqA
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    'Set new shift in |LHJRP-Z  
    op.Type = "ShiftZ" U( YAI%O  
    op.val1 = taq *}?[tR5  
    op.parent = parID Dd3f@b[WX  
    AddOperation eID, op i_Kwxn$  
    Print "Set aqueous humor thickness = " & taq-0.55 zp:dArh0  
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    '************************************************************************* =7Ln&t
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    'Radius and conic constant of anterior lens ("$/sT  
    '************************************************************************* peQwH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ltlp9 S  
    GetConic eID, entity, curv, conic /<LZt<K  
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    SetConic eID, entity, 1/Rant, CCant 5{c;I<0  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ayz*2N`%  
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    '************************************************************************* TCr4-"`r-{  
    'Radius and conic constant of posterior lens T(J'p4  
    '************************************************************************* ER0 Yl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) EX8JlA\-W  
    GetConic eID, entity, curv, conic d?,'$$aB  
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    SetConic eID, entity, 1/Rpost, CCpost c[dSO(=  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :4ryi&Y  
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    '************************************************************************* x/|W;8g4  
    'Lens thickness (Position of posterior lens surface) (q)}`1d'  
    '************************************************************************* *"%TAe7?~+  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z 3BwbH  
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    ' Delete any z-shift(s) f|[7LIdh-  
    count = 0 bI):-2&s}  
    While GetOperationCount(eID)>count {u'szO}k  
        GetOperation eID, count, op ,jU>V]YC  
        If op.Type="ShiftZ" Then qu=~\t1[6  
            DeleteOperation eID,count 1w,_D.1'  
            count=count-1 ]so/AdT9hA  
        End If crmQn ^4\  
        count=count+1 Llfl I  
    Wend rQ*+ <`R}  
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    'Set new z-shift _l d.Xmvd  
    op.Type = "ShiftZ" 0'^M}&zCi  
    op.val1 = tlens ,K5K?C$k  
    op.parent = parID ddn IKkOp  
    AddOperation eID, op {K^5q
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    Print "Set lens thickness = " & tlens |G j.E  
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    '************************************************************************* 5 jrR]X  
    'Lens index of refraction ZO+RE7f*?c  
    '************************************************************************* tXE/aY*I  
    eID = FindMaterial( "Lens" ) a>4/2#J  
    GetModelMaterial eID, mat Xdvd\H=  
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    mat.Nd = nlens eI8o#4nT  
    SetModelMaterial eID, mat NdK`-RT  
    Print "Set lens index of refraction = " & nlens $^x=i;>aK.  
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    '************************************************************************* ^
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    'Pupil diameter #MC#K{Xd  
    '************************************************************************* ,Ag{-&  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) GM|&,}  
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    'Adjust pupil diameter (trimming volume inner hole) K1 f1T  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" kQ\GVI11?  
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    ' Adjust pupil location to just in front of the lens ~Wrp
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    parID = FindFullName( "Geometry.Arizona Eye" ) oodA&0{)d  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rO87V!Cj  
    count = 0 [^"}jbn/  
    While GetOperationCount(eID)>count 2> a&m>  
        GetOperation eID, count, op ;~3;CijJ8  
        If op.Type="ShiftZ" Then FPc`J  
            DeleteOperation eID,count pH~\~  
            count=count-1 [s}W47N1  
        End If }T_"Vg q  
        count=count+1 tI^91I  
    Wend GRc)3 2,  
    op.Type = "ShiftZ" V_i&@<J  
    op.val1 = taq-0.01 PKlR_#EB?  
    op.parent = parID EU(e5vO  
    AddOperation eID, op !(*&P  
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    Print "Set pupil diameter = " & pupilDiam PqspoH 0OI  
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    'Update AZ Eye subassembly Description N
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    eID = FindFullName( "Geometry.Arizona Eye" ) FH</[7f;@N  
    GetEntity eID, entity ,e'r 0  
    entity.Description = "Accommodation = " & A & "D" ;CO qu#(  
    SetEntity eID, entity b>5*G1  
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    Update G}U <^]c  
    Print "DONE!" ~n -N  
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End Sub 2)BO@]n  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： gX"  
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Accommodation = 4 Diopters KKwM\  
Pupil Diameter = 4 mm RIkIE=+6  
Set aqueous humor thickness = 2.81 8kKL=  
Set anterior lens radius = 10.4 and conic constant = -2.375869 NG3?OAQTw  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 5,xPB5pK  
Set lens thickness = 3.927 ybpOk  
Set lens index of refraction = 1.42672 CUDA<Fm  
Set pupil diameter = 4 7a[6@  
DONE! 0 Rb3|te